Tris(trimethylsilyl)silyl versus tris(trimethylsilyl)germyl: Radical reactivity and oxidation ability
作者:Jacques Lalevée、Nicolas Blanchard、Bernadette Graff、Xavier Allonas、Jean Pierre Fouassier
DOI:10.1016/j.jorganchem.2008.08.039
日期:2008.11
(TMS)3SiH toward the t-butoxyl, the t-butylperoxyl and the phosphinoyl radicals. A similar behavior is noted for an aromatic ketone triplet state. II exhibits a lower absolute electronegativity: accordingly, the addition to electron rich alkenes is less efficient than for I. Radical II is also found less reactive for both the peroxylation (II+O2→II-O2) and the halogen abstraction reactions. The rearrangement
提供了三(三甲基甲硅烷基)甲硅烷基I和三(三甲基甲硅烷基)甲锗烷基II自由基反应性的比较。通过激光闪光光解,量子力学计算和电子自旋共振(ESR)实验检查了它们的形成以及在多种化学过程(双键加成,卤素抽象,过氧自由基形成等)中遇到的反应性。起始化合物(TMS)3 GeH比(TMS)3 SiH对叔丁氧基,叔丁基过氧基和膦酰基具有更高的反应性。对于芳族酮三重态也观察到类似的行为。II表现出较低的绝对电负性:因此,向富电子的烯烃中添加的效率低于I的效率。还发现自由基II对于过氧化(II + O2→II-O2)和卤素提取反应均具有较低的反应性。II-O2的重排比I-O2的重排慢;这与过程各自的放热有关。